Acoustical Behavior Of Churches: Mudejar-Gothic Churches

Christian churches have traditionally been considered to have very good acoustical behavior. This unfounded belief has led to important en-on in church rehabilitation works, especially when the church is to be used subsequently as an auditorium or theater; this is the case of many churches in Spain. Our research group has worked in acoustical analysis for more than ten years. We have participated in many cases of church rehabilitation and have had the opp&unity to achieve surprisingly good acwstical behavior in several. We deal with a very common type in southern Spain: Gothic-Mudejar churches, which have a small volume, a triple-nave layout, and wooden ceilings

Public sector wage gaps in Spanish regions.

This paper provides an approximation to the measurement of public sector wage gaps in Spanish regions. By using data from the European Community Household Panel, it is shown that the balance between what private firms pay in the local market and what the public sector pays, differs substantially in different areas of the country. Public sector wage differences among Spanish regions are mostly due to differences in returns, not to differences in characteristics or to selection effects, and are not constant across gender, educational levels, or occupations. Moreover, in those regions where Regional Governments have a higher weight in public employment, public wage gaps are higher and public employers pay higher returns. There also seems to be a cross-regional positive correlation between public wage gaps and unemployment, and a negative one between labour productivity and public wage gaps. Hence, a tentative conclusion is that the incentives to select into the public sector are higher in the low productivity regions, precisely those where scarcity of human capital in the private sector may be the most important factor for explaining economic backwardness.public sector, wage differentials, switching regressions, Spanish regions.

Entanglement detection in coupled particle plasmons

When in close contact, plasmonic resonances interact and become strongly correlated. In this work we develop a quantum mechanical model, using the language of continuous variables and quantum information, for an array of coupled particle plasmons. This model predicts that when the coupling strength between plasmons approaches or surpasses the local dissipation, a sizable amount of entanglement is stored in the collective modes of the array. We also prove that entanglement manifests itself in far-field images of the plasmonic modes, through the statistics of the quadratures of the field, in what constitutes a novel family of entanglement witnesses. This protocol is so robust that it is indeed independent of whether our own model is correct. Finally, we estimate the amount of entanglement, the coupling strength and the correlation properties for a system that consists of two or more coupled nanospheres of silver, showing evidence that our predictions could be tested using present-day state-of-the-art technology.Comment: 8 pages (6 main text + 2 supplemental), 3 figure

Quantum Ratchets for Quantum Communication with Optical Superlattices

We propose to use a quantum ratchet to transport quantum information in a chain of atoms trapped in an optical superlattice. The quantum ratchet is created by a continuous modulation of the optical superlattice which is periodic in time and in space. Though there is zero average force acting on the atoms, we show that indeed the ratchet effect permits atoms on even and odd sites to move along opposite directions. By loading the optical lattice with two-level bosonic atoms, this scheme permits to perfectly transport a qubit or entangled state imprinted in one or more atoms to any desired position in the lattice. From the quantum computation point of view, the transport is achieved by a smooth concatenation of perfect swap gates. We analyze setups with noninteracting and interacting particles and in the latter case we use the tools of optimal control to design optimal modulations. We also discuss the feasibility of this method in current experiments.Comment: Published version, 9 pages, 5 figure

Correlated hopping of bosonic atoms induced by optical lattices

In this work we analyze a particular setup with ultracold atoms trapped in state-dependent lattices. We show that any asymmetry in the contact interaction translates into one of two classes of correlated hopping. After deriving the effective lattice Hamiltonian for the atoms, we obtain analytically and numerically the different phases and quantum phase transitions. We find for weak correlated hopping both Mott insulators and charge density waves, while for stronger correlated hopping the system transitions into a pair superfluid. We demonstrate that this phase exists for a wide range of interaction asymmetries and has interesting correlation properties that differentiate it from an ordinary atomic Bose-Einstein condensate.Comment: 24 pages with 9 figures, to appear in New Journal of Physic

On the resonances and polarizabilities of split ring resonators

In this paper, the behavior at resonance of split ring resonators SRRs and other related topologies, such as the nonbianisotropic SRR and the broadside-coupled SRR, are studied. It is shown that these structures exhibit a fundamental resonant mode the quasistatic resonance and other higher-order modes which are related to dynamic processes. The excitation of these modes by means of a properly polarized time varying magnetic and/or electric fields is discussed on the basis of resonator symmetries. To verify the electromagnetic properties of these resonators, simulations based on resonance excitation by nonuniform and uniform external fields have been performed. Inspection of the currents at resonances, inferred from particle symmetries and full-wave electromagnetic simulations, allows us to predict the first-order dipolar moments induced at the different resonators and to develop a classification of the resonances based on this concept. The experimental data, obtained in SRR-loaded waveguides, are in agreement with the theory and point out the rich phenomenology associated with these planar resonant structures.MEC (España)-TEC2004-04249-C02-01 y TEC2004-04249-C02-02Comunidad Europea (programa Eureka)-2895 TELEMACAgencia de Subvenciones de la República Checa-102/03/044